WO1998010033A1

WO1998010033A1 - Solvent for solid crude oil deposits

Info

Publication number: WO1998010033A1
Application number: PCT/IB1996/000903
Authority: WO
Inventors: Zinaida T. Dimitrieva
Original assignee: Destiny Oil Anstalt
Priority date: 1996-09-09
Filing date: 1996-09-09
Publication date: 1998-03-12
Also published as: AU6751796A

Abstract

Environmental protection, cleaning of tanks, bulk oil containers, pipelines from solid asphalt tar and paraffin hydrate oil deposits (residues), washing oil products out of beach sand, soils and earth, deparaffinisation of oil beds and pre-face areas of wells. Solvent for solid crude oil deposits, containing an organic extracting substance, distinguished by the fact that it contains a neutral transporting fluid (TF), a dissolving (extracting) substance (DS) and a surfactant in a specific ratio of constituents (mass %) - DS:5-60; surfactant: 0.01-0.8; TF:39.2-94.99. The solvent contains water as the TF, and aromatic, alkyl-aromatic and aliphatic hydrocarbons fractions, and mixtures of these fractions in any mass ratio as the DS.

Description

SOLVENT FOR SOLID CRUDE OIL DEPOSITS

TECHNICAL FIELD

The invention relates to the field of environmental protection. The invention can be successfully applied to the cleaning of tanks, to asphalt tar deposits (residues) of oil, and to the washing clean of sand on beaches, agricultural soils, and base material on oil-extraction sites polluted by heavy oil products, and in case of emergencies during the transportation of oiL

The invention can also be applied, with great success, to the dissolution of paraffin and paraffin hydrate deposits in main oil pipelines and pump compressor pipes, and in the technology of de- paraffinisation of oil-bearing beds in the pre-face area of wells.

BACKGROUND ART

There are no universal methods or devices for cleaning oil, asphalt tar deposits and paraffin deposits off different surfaces (smooth, porous, etc.)..

Devices are known for cleaning paraffin off pipes, the basic structural elements of which are a moving automatic scraper (patent RU 2023868, E21 B 37/02), a shaft with turbines (patent RU 2010952, E21 B 37/02), and a linear heater (patent RU 2123867, E21 B 37/02). The basic elements in the device for washing down sand are a rotating desintegrator and a pneumatic manifold (patent RU 1577832, B03 B 5/00).

To destroy paraffin hydrate deposits in the pre-face area of oil wells, de-emulsifying liquids are pumped into the bed, which contain production oxides of ethylene, propylene and fatty spirits (patent RU 2027730, CO9 R 3/00), and alkaline metals are also pumped into the operational area of the bed (lithium, sodium, potassium, or composites based on them), dispersed in the proportion of 10.75 mass% in de-watered hydrocarbon liquid, with subsequent pumping in of water in the proportion of 50 - 200 parts by mass to 1 part by mass of metal (patent RU 2028447, E21 B 37/06). A fluid which takes the form of a residual product from the processing of sulphurous oil raw material, with a high trimethylbenzene content (30 - 70% mass%.), is used as a washing liquid for cleaning up paraffin-asphalt deposits from oil and gas wells (patent PCT 94/19575, E21 B 37/06).

With the aim of avoiding the formation of asphalt-tar-paraffin deposits and reducing the hydraulic resistance of highly viscous oils during their extraction and transportation through the pipeline, a compound is used based on 5 - 10 mass% non-ionogenic surfactant, 20 - 24 mass% N, N-dialkyl- N,N-diallyl ammonia chlorides, or their co-polymers, with acrylic acid, and 66 - 75 mass% sodium alkyl sulphonate (patent RU 1132535, E 21B 37/06), the concentration of which in water is 0.05 - 0.2 mass%.

A complex compound has been proposed, together with the graduated extraction (precipitation) of paraffins from oil at normal and increased temperatures (patent US 5196116, CIO G 73/06). For the prior recovery of precipitated paraffins, the compound contains (depending on their molecular mass) water, ketones, alcohols, aldehydes and acids. The compound for the precipitation of paraffins is found in the solvent in a proportion of 1:10.

Known methods of washing soils and ore sands clean of oil and oil products are based on the principles of dispersion of material in the washing medium, with the subsequent sedimentation of washed-out particles (patent FR 2499119, E01 H 12/00, patent RU 1694222, B03 B 5/02).

A substance for extracting gasoline from the soil, developed by the U.S. Environmental Protection Agency, contains a mixture of acetone and methylene chloride in a weight ratio of 1 : 1 (Donaldson, S.G., Miller, G.C., Miller, W.W.: Extraction of gasoline constituents from soil / J. Assoc. Offic. AnaL Chem. - 1990 - voL 73, no. 2 - pp. 306 - 311). The significant drawbacks to the known extractant are the very low grade of gasoline extraction from the soil (the degree of extraction of gasoline from the dry soil is 43.2%, and for moist soil scarcely 21.8%), high toxicity, the danger of explosion from the acetone, and a complicated process for the extraction of the extractant from the oil products. In addition, the use of the known extractant, containing methylene chloride, for the extraction (removal) of oil from the soil is made more difficult (more complicated) by the fact that the chloro-organic compounds poison oil processing catalysts.

DISCLOSURE OF INVENTION

The objective of the given invention is to develop an aqueous organic two-phase solvent for removing solid asphalt tar and paraffin deposits from the surface of containers and pipes intended for the storage and transport of oil, for the washing of sand, soil and other solid materials from oil (oil products) and also for the de-paraffinisation of oil beds.

The technical result is achieved in that the solvent compound for crude and solid oil deposits, based on polar organic liquids, according to invention, contains a working (transport) fluid and a dissolving (extracting) substance, emulsified or suspended in the working fluid, with the help of a surfactant. The compound developed according to invention contains water (sea water, fresh water, recycled water) as the working fluid contains fractions (mixtures) of aromatic hydrocarbons, fractions (mixtures) of alkyl-aromatic hydrocarbons with a number of alkylic groups in the aromatic nucleus - up to three as the dissolving (extracting) substance and with a number of carbon atoms in the alkylic fragment or a substitute from C2 to C , mixtures of fractions of aromatic and alkyl- aromatic hydrocarbons in any combination and mass ratio as well as fractions of aromatic and alkyl- aromatic hydrocarbons in a mixture with fractions of aliphatic hydrocarbons, C₅ - Cι₂, in any combination and mass ratio of these fractions. As its surfactant, the solvent contains polyalkylphenols, alkyl-carbolic acids C10 - Cπ, polyglycols and compounds from the following classes: alkyl (aiyl) sulphonoles, carboxoles, polyalkyl (polyaryl) sulphonoles, and polyalkyl (polyaryl) carboxoles.

With the objective of increasing the dissolving (extracting) capacity of a solvent for solid asphalt tar oil residues according to invention, it is preferable to iclude in its composition fractions of aromatic and alkyl-aromatic hydrocarbons, emulsified with water with the help of polyalkylphenoles or alkyl (aryl) sulphonoles. To remove solid paraffin deposits from the rock or from the surface, it is preferable to use fractions of aliphatic hvdrocarbons in the composition of the solvent, or their mixtures with fractions of alkyl-aromatic hydrocarbons, emulsified with water, with the help of alkyl carbolic acids C₁₀ - Cπ, polyalkyl phenoles, carboxoles, and polyalkyl (polyaryl) carboxoles. With the objective of increasing the degree of emulsification (homogenisation) of the hydrocarbons with the water, and the stability of the emulsion, it is preferable to use alkyl (aryl) sulphonoles and polyalkyl (polyaryl) sulphonoles as surfactant.

Uniform distribution of the dissolving (extracting) substance (hydrocarbons) through the entire volume of the neutral transporting (working) fluid (water) sharply reduces the volatility (evaporability) of the hydrocarbons, and provides a compound for the dissolution of solid oil deposits which creates practically no fire or explosion hazards. Uniformity of dispersal of hydrocarbons in the water, according to invention, is achieved with the help of the surfactant and agitation (turbulization).

The compound for the dissolution of oil residues, according to invention, is prepared and applied without heating (at ambient temperature).

The compound according to invention is more effective in dissolving oil residues, and has optimal technical operation characteristics, with the following makeup and ratio of constituents (mass%):

Dissolving substance (DS) 5 - 60

Surfactant 0.01 - 0.8

Transporting fluid (TF) 39.2 - 94.99

With the objective of increasing (improving) the efficiency of the solvent in the de-paraffinisation of oil beds, according to invention, its composition also includes sodium carbonate and hydrochloric (acetic) acid in the following ratio of constituents (mass%):

DS ⁵ - ⁶⁰

Surfactant °-⁰¹ - °-⁸

Na₂CO₃ 0.01 - 3.0

Hydrochloric (acetic) acid ^{0 03} -¹⁰-⁰ TF 26.2 - 94.95

In this connection, the hydrochloric (acetic) acid is not introduced into the solvent at first. The hydrochloric (acetic) acid is pumped into the paraffin-impregnated oil bed at the same time as the solvent.

Instead of the sodium carbonate and the hydrochloric (acetic) acid, it is preferable, in a solvent compound exceeding 100%, to introduce carbonic acid by passing CO2 through the solvent until it is completely saturated.

The technology for preparing the compound consists of a simple (mechanical or ultra-sonic) mixing of the constuents without heating. The sequence in which the constituents are mixed in has little influence on the end result. However, it is preferable to dissolve the surfactant into the TF first, and then to add the DS to the solution, or to mix the surfactant into the DS first and then introduce this mixture into the TF during intermixing. The compound can be prepared a long time before it is used, or before its initial application.

The efficiency of the dissolution (extraction) of solid asphalt tar oil residues depends on how long they are in contact with the solvent and on the intensity of the intermixing (turbulization). As the dissolution of the oil proceeds, the saturated hydrocarbon fraction of the solvent separates from the transporting fluid - the water. When the maximum amount of residues has been dissolved, the upper layer, consisting of a hydrocarbon solution of asphalt tar and paraffin substances, is separated from the aqueous layer and the hydrocarbons are driven off (evaporated). The separated water and the substances driven off after the dissolution of the residues can be used many times for the same purpose. The amount of dissolved oil residues depends on the makeup and the mass of the DS and surfactant, and lies between 51 and 110 mass% in relation to the DS.

The asphalt tar and paraffin substances separated out from the oil residues (deposits) with the help of the solvent can be sent for processing or utilisation.

The presence of solventing substance in the dissolution product of the oil residues does not constitute a risk as regards their processing or utilisation. MODES FOR CARRYING OUT THE INVENTION

Example 1

Take a mixture of aromatic hydrocarbons comprising benzene, toluol, xylol and cumol in equal mass ratios. 0.02 g (0.01 mass%) of polyalkyl phenole is dissolved in 10 g (5 mass%) of the mixture. This solution is suspended in 189.98 g (94.99 mass%) of fresh water. With the compound created, and at normal temperature, portions of oxydized tar are dissolved until the hydrocarbon fraction of the solvent is completely saturated. 9 g of tar are dissolved in this compound, which constitutes 90 mass% in relation to the mixture of aromatic hydrocarbons.

Example 5

0 . 2 g (0.01 mass%) of polyalkyl phenole is dissolved in

100 g (50 mass%) of a mixture of aromatic hydrocarbons. This solution is suspended in 100 g

(50 mass%) of fresh water. Portions of oxydized tar are dissolved in the resulting compound at normal temperature until the hydrocarbon fraction of the solvent is completely saturated. 98 g of tar are dissolved in this compound, which constitutes 98% by mass in relation to the mixture of aromatic hydrocarbons.

Example 9

0.2 g (0.1 mass%) of polyalkyl phenole is dissolved in 79.8 g (39.9 mass%) of sea water, 120 g (60 mass%) f the mixture of aromatic hydrocarbons is added and the compound is suspended. Portions of oxydized tar are dissolved in the resulting compound at normal temperature until the hydrocarbon fraction of the solvent is completely saturated. 98.4 g of tar are dissolved in this compound, which constitutes 82 mass% in relation to the mixture of aromatic hydrocarbons.

The results, listed under the examples shown in the table 1, were achieved in an analogous manner.

TABLE I - SOLVENT FOR SOLID OIL RESIDUES Solvent compound, mass% Solubility of residue, mass%

Example Water Mixture of aromatic Polyalkyl Relative to Relative to entire number hydrocarbons phenol organic composition fraction

1 95 5 0.01 90.0 9.0

2 90 10 0.01 95.0 9.5

3 90 9.9 0.1 99.0 9.9

4 89.6 9.9 0.5 84.3 8.8

5 50 50 0.01 98.0 49.0

6 74.5 25 0.8 51.0 13.0

7 64.9 35 0.1 91.5 32.1

8 74.9 25 0.1 97.0 24.3

9 39.9 60 0.1 82.0 16.4

10 49.9 50 0.1 90.5 45.2

Example 11

Take a mixture of alkyl-aromatic hydrocarbons, comprising di-ethyl benzene, tri-isopropyl benzene, diheptyl benzene, undetsil benzene and octiltoluol in equal mass ratios. 0.05 g (0.025 mass%) of polyvinyl benzil sulphonole is dissolved in 100 g (50 mass%) of a mixture of alkyl-aromatic hydrocarbons. This solution is suspended in 100 g (50 mass%) of sea water. Portions of solid oil residues taken from a bulk oil container (cistern) are dissolved in the resulting solution at normal temperature. The solid resdiues are dissolved until the hydrocarbon fraction of the solvent is completely saturated. 110 g of residues are dissolved in this compound, which constitutes 110 mass% in relation to the mixture of aromatic hydrocarbons.

Example 12

Take aliphatic hydrocarbon fraction C5 - Cβ (AHF) in accordance with the following mass ratio of the hydrocarbons- C_s: & C₇: C₈ = 5: 10: 70: 15.

To wash down 5 g of sand, contaminated with 20 mass% of oil, add 40 g of solvent to it, containing 36 g of water and 4 g of aliphatic hydrocarbon fraction, with a ratio of solvent to sand of

8 : 1, and intermix over a 15-minute period. After settling the liquid is separated from the sand, the hydrocarbon solution is separated from the aqueous solution, and the water is used in a new cycle of cleaning sand from oϋ The sand is dried and weighed. The degree of cleaning of the sand is 71 mass%.

Example 13

40 g of solvent, comprising 36 g of water, 3.98 g of aliphatic hydrocarbon fraction, and 0.02 g of alkyl carbolic acids fraction Cι₀ - Cπ (ACA do - Cπ), is added to 5 g of sand, contaminated by 20% of oil by mass, with a ratio of solvent to sand of 8 : 1 , and the mixture is intermixed for a 15- minute period. After settling the liquid is separated from the sand, the hydrocarbon solution of oil is separated from the aqueous solution, and the water is used in a new cycle of cleaning sand from oϋ The sand is dried and weighed. The degree of cleaning of the sand is 93 mass%.

Example 14

40 g of solvent, comprising 34 g of water, 5.94 g of aliphatic hydrocarbon fraction, and 0.06 g of alkyl carbolic acids fraction Cι₀ - Cπ is added to 5 g of sand, contaminated by 20% of oil by mass, with the solvent to sand ratio 8 : 1, and the mixture is intermixed for a 15-minute period. After settling, the liquid is separated from the sand, the hydrocarbon solution of oil is separated from from the aqueous solution, and the water is used in a new cycle of cleaning sand from oϋ The sand is dried and weighed. The degree of cleaning of the sand is 96 mass%.

All the remaining results for the cleaning of sand from oil shown in Table 2 were obtained in an analogous manner.

TABLE 2 - SOLVENT COMPOUND FOR CLEANING GROUND OF OIL Example Solvent compound, mass% Degree of Number cleaning of ground, %

Water Aliphatic Alkyl carbolic hydrocarbon acid fraction fraction Cs-C₈ Cio-Cπ

15 95 5 0 71

16 90 10 0 92

17 85 15 0 94

18 95 4.95 0.05 74

19 90 9.95 0.05 93

20 90 9.90 0.10 94

21 90 9.85 0.15 93

22 85 14.85 0.15 98

Solvent compounds using polyethylene glycol, polypropylene glycol or polyvinyl bcnzenecarboxole as surfactant clean up to 85 - 98% of sand from oil and fuel oil under analogous conditions.

Example 23

An oil bed can be de-paraffinised with the help of a solvent compound in the following manner. Filtering capacity of the oil bed is isolated by paraffin.

0.6 g (0.3 mass%) of polyethylene glycol and 0.4 g (0.2 mass%) of alkylcarbonic acid fraction do - C₁₇ or polyalkyl phenole are dissolved in 143 g (71.5 mass%) of water at normal temperature during intermixing. 56 g (28 mass%) of aliphatic hydrocarbon fraction or alkyl-aromatic hydrocarbon fraction, or a mixture of these fractions, are added to this solvent during intermixing. The resulting dispersion is filtered through a model of the bed containing paraffin. Following the de-paraffinisation of the bed, oil is pumped into it, and the oil permeability of the bed rises to 81.7% (mean value). Example 24

Filtering capacity of the oil bed is isolated by paraffin- 0.6 g (0.3 mass%) of polyethylene glycol and

0.4 g (0.2 mass%) of alkylcarbonic acid fraction Cio - Cπ or polyalkyl phenole are dissolved in 143 g (71.5 mass%) of water at normal temperature during intermixing. This solution is saturated with

CO₂, and 56 g (28 mass%) of aliphatic hydrocarbon fraction or alkyl-aromatic hydrocarbon fraction, or a mixture of these fractions, are added to it. The resulting dispersion is filtered through a model of the bed containing paraffin. Following the de-paraffinisation of the bed, oil is pumped into it, and the oil permeability of the bed rises to 95.3% (mean value).

Example 25

Filtering capacity of the oil bed is isolated by paraffin. 0.6 g (0.3 mass%) of polyethylene glycol, 0.4 g (0.2 mass%) of alkylcarbonic acid fractions Cio - d₇ or polyalkyl phenole, and 1.6 g (0.8 mass%) Na₂CO₃ are dissolved in 121.4 g (60.7 mass%) of water at normal temperatures during intermixing, and 56 g (28 mass%) of aliphatic hydrocarbon fraction or alkyl-aromatic hydrocarbon fraction, or a mixture of these fractions, are added. The resulting dispersion and 20 g (10 mass%) of hydrochloric acid are simultaneously pumped into a model of the bed containing paraffin. Following the de-paraffinisation of the bed, oil is pumped into it, and the permeability of the oil bed rises to 92% (mean value).

Claims

1. Solvent for solid crude oil deposits, containing an organic extracting substance, is distinguished by the fact that it includes a neutral transporting fluid (medium), a dissolving (extracting) substance, and a surfactant in a specific ratio of components (mass%) :

Dissolving (extracting) substance 5 - 60

Surfactant 0.01 - 0.8

Transporting fluid (medium) 39.2 - 94.99

2. Solvent for solid crude oil deposits as paragraph 1, is distinguished by the fact that it contains water (sea water, fresh water or recycled water) as a transporting (working) fluid.

3. Solvent for solid crude oil deposits as paragraph 1, is distinguished by the fact that aromatic hydrocarbons fractions (mixtures) or alkyl-aromatic hydrocarbons fractions (mixtures), with any number ofalkyl groups up to three in the aromatic nucleus and with any number of hydrocarbon atoms in the alkyl fragment from C₂ to Cu, or mixtures of aromatic and alkyl- aromatic hydrocarbons fractions in their mass ratios, or mixtures of aromatic, alkyl- aromatic and aliphatic (C₅ - C₁₂) hydrocarbons, with their mass ratios are used as a dissolving (extracting) substance. The hydrocarbons in the fractions have equal and/or unequal mass ratios.

4. Solvent for solid crude oil deposits as paragraph 1, is distinguished by the fact that it contains polyalkyl phenoles, alkylcarbolic acids Cio - Cπ, polyglycols and/or compounds from the following classes: alkylsulphonoles (arylsulphonoles), carboxoles, polyalkyl sulphonoles (polyaryl sulphonoles), and polyalkyl carboxoles (polyaryl carboxoles), as the surfactant.

5. Solvent for solid crude oil deposits as paragraph 1, is distinguished by the fact that the technology for preparing the solvent takes the form of mechanical or ultra-sonic intermixing of the components, without the use of heating, in the following sequence: (surfactant + transporting fluid) + dissolving substance, or (surfactant + dissolving substance) + transporting fluid.

6. Solvent for liquid crude oil deposits as paragraph 1, is distinguished by the fact that, for dissolving paraffin in an oil bed (de-paraffinisation of bed), it also contains sodium carbonate and hydrochloric (acetic) acid, in the following components ratio (mass%) :

Dissolving (extracting) substance 5-60

Surfactant 0.01-0.8

Na₂CO ₃ 0.01-3.0

Hydrochloric (acetic) acid 0.03-10.0

Transporting fluid 26.2-94.95

or the solvent contains more than 100% CO2, until the solvent is completely saturated.

7. Solvent for crude oil solid deposits as paragraph 1, is distinguished by the fact that the transporting fluid and the dissolving (extracting) substance do not undergo any chemical changes and do not interact with the oil deposits, and can be used repeatedly, after being recovered, in the technology for dissolving (extracting) asphalt tar and paraffin residues.